Cameras and in particular the image sensor of a camera is very sensitive to heat. The image quality delivered from an image sensor degrades significantly at rising temperature. Additionally, the electronics of a camera including an image sensor is also sensitive to heat. Performance of electronics are compromised by the heat, it is even possible that the heat permanently damages the electronics.
The electronics and the image sensors in modern cameras are therefore often thermally coupled to heat sinks. Heat sinks are passive components which dissipates the heat into the surrounding air. These cooling systems are traditionally equipped with mechanical fans directing airflow across the heat sink for increased cooling effect. However, when the temperature of the surrounding air increases these systems have more and more trouble in transporting heat away from the camera components and the camera.